1. Field of the Invention
The present invention relates to a plasma process application system. More particularly, the present invention relates to an advance process control (APC) system and a multivariate analysis monitoring method for a plasma process machine.
2. Description of Related Art
Plasma process is one of the most important processes in semiconductor process, which may include processes such as deposition, etching, and cleaning. In particular, plasma-enhanced deposition process, such as plasma-enhanced chemical vapor deposition (PECVD) or high density plasma CVD, has been broadly applied to film depositions in semiconductor devices. Usually different material layers are obtained by changing various parameters of a plasma process machine within a plasma deposition chamber.
However, when abnormity occurs in a plasma process due to the instability of the plasma process machine, the abnormal semiconductor device cannot be detected with existing testing method until the entire semiconductor device has been completed. Therefore, the manufacturing cost is very high and the process time is also wasted.
Accordingly, a method for stabilizing the plasma process machine and an apparatus thereof is very important.